Organics processing facilities

Processing organics on a commercial scale increases the community's ability to recover and conserve resources and reduces the quantity of organics going to landfills. Recycled organics applied to land can provide multiple benefits to soil health and crop growth, including improved soil structure, improved water retention and higher yields.

Organics processing facilities require planning consent and,
depending on size, may also require an environmental protection licence.
Guidelines and standards are available to help plan and operate well-designed,
purpose-built composting facilities.

These facilities share the important responsibility, along
with everyone in our community, to help protect the environment.How
you manage a facility affects the surrounding community. Maintaining good local
relationships is the basis of your social licence to operate.

Managing contamination

When licensed composting facilities receive organics
material for recycling, they must comply with allowed materials, as specified
in the facility's environment protection licence.

Composting facilities should negotiate with generators of
organics material to ensure contamination in materials falls within acceptable
levels.

Statutory requirements for land application of compost products

Managers and operators of organics processing facilities
need to be aware of a range of statutory requirements that apply
to the land application of recycled organics. These regulatory
measures ensure human and animal health and the environment are protected
when these materials are put on the land.

Resource recovery orders and exemptions

The Protection of the Environment Operations Act
1997 (POEO Act) states that waste cannot generally be applied to land
without the need to hold an environment protection licence and/or pay the waste
levy.

However,
recycled wastes can be applied to land if they are made and used in accordance
with the resource recovery orders
and exemptions.

Orders (conditions for generators and processors)and
exemptions (conditions for consumers) are issued as a package by the EPA only
when it has been demonstrated that the re-use

is genuine, rather than another means of waste
disposal

is beneficial or fit-for-purpose, and

will not cause harm to human health or the
environment

General
resource recovery orders and exemptions are for commonly recycled and re-used,
high-volume, and well-characterised waste materials including garden organics, food waste, manures, biosolids,
mulch and agricultural crop wastes. It is the responsibility of facility
operators to ensure that they and their customers are aware of the orders and
exemptions obligations.

Where no order or exemption is available for a specific
material, processing method or intended use of waste, facility
managers shouldapply for an order or exemption.

What is compost?

In nature, organics
material gradually decomposes and returns nutrients back to the soil. Licensed
composting processors use various systems to speed up this natural process.

Composts today are
made from materials such as food and garden organics from household green bins,
green waste from commercial landscaping activities, or commercial food wastes.

Different composting technologies can be used to
produce quality, fit-for-purpose products. These technologies include aerobic
composting systems, turned windrow systems, aerated state pile and in-vessel
systems.

Turned windrow

Mechanical turning of an organics windrow

This composting system uses horizontal piles, formed by a
front-end loader or windrow turner, and aerated by mechanical turning.

The piles are generally 1.5 to 3 m in height, their length limited
by composting pad size.

Aerated static pile

This composting method uses a blower to aerate a free-standing
pile, moving air through perforated pipes located beneath the pile.

In-vessel

In this system composting takes place in an enclosed chamber
or vessel, which typically controls the composting process by regulating the
rate of mechanical aeration.

Aeration helps remove heat, and control temperature and
oxygenation. The blower used to aerate the chamber can operate in a positive
(blowing) and/or negative (sucking) mode. The aeration rate can be controlled using
temperature, oxygen or carbon dioxide feedback signals.

Anaerobic digestion

This organics treatment system uses microbial action to
decompose organics material in a solid, semi-solid or liquid phase in the
absence of oxygen. Part of the organics fraction is converted to carbon dioxide
and methane.

Methane recovered must be purified to remove carbon dioxide,
in most cases, if it is to be burned for energy.

Anaerobic digestion mostly occurs at moderate (mesophilic)
temperatures. In some systems, the methane recovered is used to heat the
reaction chamber to higher (thermophilic) temperatures to speed up the
digestion process.

Vermiculture

In vermiculture composting processes, organic matter is
broken down primarily by worm species.

Commercial vermiculture systems include

windrows or beds

stackable trays

batch-flow containers

continuous flow containers

The systems described above relate mainly to the processing
of source-separated organic materials. Some facilities in NSW accept food and
garden organics mixed in the red lid bins from municipal, commercial or
industrial collections.